Has anyone had experience with the addition of an auxiliary fuel tank for the LMM? Any issues with the size of the factory fuel tank (26 gal) vs the new combined tank capacity. What will be the effect on regen, if any? Should the chip be reprogrammed for the new fuel tank size? I haven't done this yet, but need more range than the 26 gal factory tank provides.

You have a 26 gallon? The most I've been able to get in it was a hair over 22 when it was pretty empty.

You have a 26 gallon? The most I've been able to get in it was a hair over 22 when it was pretty empty.


Thats because it wasn't "pretty empty"... light comes on LONG before you're running on fumes. I've had the light come on and had to drive 70 miles towing a 10k trailer, averaging about 12mpg... i figure you've got about 6 gallons left when the light comes on :)

With a 32 gallon tank i usually fill 26 gallons when the light turns on.

I had the stock tank replaced in my crew cab short bed by Aero Tanks in Corona CA. They were able to get about 53 gallons in it as as special request. Standard is 48 gallons. No codes, fuel gauge works the same.
It is sweet, had one in my LLY also

hey 24z06 did aero charge any more for the extra cap and was it 2 day job .like they say. i want it done also but << not yet

i just took the titan suppertank out of my lly to replace the factory tank.

Thats because it wasn't "pretty empty"... light comes on LONG before you're running on fumes. I've had the light come on and had to drive 70 miles towing a 10k trailer, averaging about 12mpg... i figure you've got about 6 gallons left when the light comes on :)

With a 32 gallon tank i usually fill 26 gallons when the light turns on.
After the last time I ran out of gas in a diesel, I never chance it. :D

One thing that concerns me about the aftermarket larger fuel tanks is that it will surround the fuel cooler, which I would assume would restrict air flow to it. I have read a few posts that say that it is not a problem, and there are several people using the tanks and all posts are positive, but there are several posts on this site that talks about putting motorcycle cooling fans on the fuel cooler to create more airflow and getting better economy. In weighing my options I decided to go with an aux 37 gallon RDS tank from Northern to put under my toolbox (haven't received yet). I didn't really want that either, but I didn't want to have any fuel cooler problems, nor did I want the larger tank to be an excuse for a dealer to give me any warranty issues. When I was looking for the larger replacement tanks I liked the Aero because it didn't seem to hang so low, but I also liked the Titan because it was plastic and larger. The part I disliked the most about the Aero is that you had to have them install it. I feel better doing some things myself. That’s my $.02. Good Luck

I added an RDS 51 gal aux tank/tool box from Northern tool to my LMM. I also purchased their install kit and have driven about 3000 miles with it. It was about a 2 hour install. I have it set up to gravity feed. When there is fuel in the aux tank the fuel gauge goes to empty after about 50 miles. It resets when you restart the vehicle or when the aux tank is empty. FWIW I have put 23 gallons in my 26 gallon factory tank.